We select 726 out of the 903 total GCs, excluding the GCs that belong to other Virgo galaxies in the core. The remaining GCs are either GCs that belong to M87 or intracluster GCs (IGCs), a population governed by the galaxy cluster gravitational potential [1]}, [2]}, [3]}, [4]}. We did this because our interest for this paper is mainly to investigate the assembly history of M87 in the cluster environment.
There are 154 Virgo galaxies that have radial velocity information in the survey region.
We used both spatial and kinematic criteria to separate the GCs bound to Virgo galaxies, following [5]}: 1) \(R < 10 R_{\rm e}\)  where \(R_{\rm e}\)  is the effective radius of a given galaxy and 2) \(|v_{\rm r}-v_{\rm gal}| < 3\sigma _{\rm gal}\)  where \(v_{\mathrm {r}}\)  , \(v_{\rm gal}\) , and \(\sigma _{\rm gal}\)  are the radial velocities of GCs, galaxy systemic velocity, and galaxy central velocity dispersion, respectively. The radial velocities of galaxies are compiled from various literature sources [6]}, [7]}, [8]}, [9]}. The velocity dispersions are from GOLDMine database [10]} compiling data from [11]} and [12]}. For the galaxies where velocity dispersions are not known, mostly faint dwarf galaxies, we adopted \(\sigma _{\rm gal} = 50\)  km s\(^{-1}\) .
